eople living on such sites. The same conclusion may be reached
in the case of inanimate things. For instance, nobody draws the light
for covered wine rooms from the south or west, but rather from the
north, since that quarter is never subject to change but is always
constant and unshifting. So it is with granaries: grain exposed to the
sun's course soon loses its good quality, and provisions and fruit,
unless stored in a place unexposed to the sun's course, do not keep
long.

3. For heat is a universal solvent, melting out of things their power of
resistance, and sucking away and removing their natural strength with
its fiery exhalations so that they grow soft, and hence weak, under its
glow. We see this in the case of iron which, however hard it may
naturally be, yet when heated thoroughly in a furnace fire can be easily
worked into any kind of shape, and still, if cooled while it is soft and
white hot, it hardens again with a mere dip into cold water and takes on
its former quality.

4. We may also recognize the truth of this from the fact that in summer
the heat makes everybody weak, not only in unhealthy but even in healthy
places, and that in winter even the most unhealthy districts are much
healthier because they are given a solidity by the cooling off.
Similarly, persons removed from cold countries to hot cannot endure it
but waste away; whereas those who pass from hot places to the cold
regions of the north, not only do not suffer in health from the change
of residence but even gain by it.

5. It appears, then, that in founding towns we must beware of districts
from which hot winds can spread abroad over the inhabitants. For while
all bodies are composed of the four elements (in Greek [Greek:
stoicheia]), that is, of heat, moisture, the earthy, and air, yet there
are mixtures according to natural temperament which make up the natures
of all the different animals of the world, each after its kind.

6. Therefore, if one of these elements, heat, becomes predominant in any
body whatsoever, it destroys and dissolves all the others with its
violence. This defect may be due to violent heat from certain quarters
of the sky, pouring into the open pores in too great proportion to admit
of a mixture suited to the natural temperament of the body in question.
Again, if too much moisture enters the channels of a body, and thus
introduces disproportion, the other elements, adulterated by the liquid,
are impaired, and the v